The Centerfor Populafion Health and Health Disparities (CPHHD) Research Model is notable for its explicit focus on the transdiscipiinary investigation of multilevel determinants of health disparities from a population perspective. Health disparities, in and of themselves, raise a number of pressing ethical and policy questions about the unequal distribution of disease risk. The pursuit of complex transdiscipiinary approaches also raise a host of concerns related to responsible research pracfice, particulariy when investigafion focuses on vulnerable communifies with significant health needs and limited capacity for active collaboration in research. These and related considerafions can be most effectively addressed by provision of a dedicated support core with expertise in empirical research and policy development as it pertains to the responsible conduct of transdiscipiinary, population-based, biomedical research. To support the work of the CPHHD, the Ethics and Policy Core therefore will: (1) conduct empiric research related to ethical and policy concerns in Latina health disparities research;(2) contribute to local, regional, and national policy development with regard to the conduct and dissemination of research relevant to Latino health disparifies;and (3) provide advice, resources, and training regarding the responsible conduct of transdiscipiinary health disparities research focused on the determinants of breast cancer among Latinas. With regard to Aim 1, core invesfigators will conduct qualitafive research focused on invesfigafing the attitudes and beliefs of Latinas approached with respect to participation in the research of the CPHHD. Interviews and focus groups will be used to explore reasons for participation, expectations regarding the near and longer-term benefits of research, perceptions regarding research-related risks, and preferences with respect to receiving results generated in the course of Center invesfigations. With regard to Aim 2, data collected as part ofthe activities of Aim 1 will be used to inform research policy development, both locally for the CPHHD as well as in collaboration with the ethics and policy cores of other Centers funded under the same mechanism. Policy development will focus on encouraging maximally effective research strategies which can be implemented in a rigorous and culturally appropriate manner. Finally, with regard to Aim 3, the core will provide required support to Center invesfigators with respect to the design and conduct of their planned investigations. Support may include advice with regard to the nature and timing of required community consultation, informed consent, study design, research dissemination, or any other concerns which may arise in the course of research. Training related to specific responsible conduct of research topics will also be available on request. These activities promise to strengthen and extend the scientific achievements of the Center.